This invention relates generally to the field of exercise devices, and more particularly to a weight training device.
The basic idea of weight training is that it exposes the human body to stimuli to which it is not accustomed. The body adjusts by growing in size so that it can manage a new load. There are several factors that determine the ability of the body to adjust to the new stress imposed upon it. These factors fall into three main categories, namely training, diet, and recuperation.
All of these factors must be met in order for a person to gain strength and endurance. The present invention is directed toward maximizing the first category, e.g. training.
Assume that a person can normally complete ten repetitions with a given weight before reaching failure. If that person performs ten repetitions in each successive training session, no progress will be made since the body has become used to and can handle this degree of resistance. If the person, however, decides to go past muscle failure and complete e.g. two more repetitions with some additional help, bringing his total to twelve repetitions, his body will adjust to this new overload by muscular growth.
It is known in the art in devices of this type to provide for the sensing of the point of muscular failure and the adjusting of the device to lighten the load so that the user can continue. The U.S. Pat. No. to Diercks, Jr., No. 4,610,449, for example, provides for the release of a number of weight plates less than the total in accordance with a predetermined time period established by a cam type timer. The Kissel U.S. Pat. No. 4,746,113 provides for a weight changing system including a body having a plurality of pins which are capable of selectively releasing the weights by pulling the requisite number of pins. It is also known to employ a motor driven variable force device to assist the user without disconnecting the weights as exemplified by the disclosure in the Berroth U.S. Pat. No. 4,921,244.
It is also known to employ computer controlled torque motors without weights for use in exercise devices which are not essentially weight lifting types, as exemplified by the Macintosh U.S. Pat. No. 4,934,694 and the Baker U.S. Pat. No. 4,930,770.
The great bulk of the prior art devises either fail to provide sufficient sensitivity to the user, or are so overly complex in design and fabrication as to be prohibitive in ccst.